The present invention relates to an ink container for an ink jet recording apparatus or the like, a valve unit for an ink container, a method for manufacturing an ink container, an ink jet head cartridge comprising an ink container, and an ink jet recording apparatus. In particular, it relates to an innovative ink container formed with the use of blow molding.
Among conventional ink jet recording apparatuses, some comprise a recording head which records on recording medium by ejecting ink, an ink container which contains ink to be supplied to the recording head, and an ink container holder as a portion which removably holds the ink container. The ink container holder also has the recording head. An ink jet recording apparatus capable of recording in color, that is, a color printer, comprises such an ink container holder that has a recording head for magenta color, a recording head for yellow color, a recording head for cyan color, and a recording head for black color, and is structured so that an ink container correspondent to each of the recording heads can be removably mounted in the ink container holder, to a position specified for each color.
There have been conceived various functions for preventing installation mistakes, so that an ink container correspondent to each of the plurality of recording heads is properly mounted to a position specified in the ink container holder in a color printer such as the one described above.
According to the first of such methods, the holder position specified for each of the different inks is labeled so that a user can visually confirm the correct holder position, or so that after ink container installation, any irregularity in ink container position is detected and a warning is displayed.
According to the second of such methods, each ink container, depending on the color of the ink it contains, is varied in the shape of the joint portion, at which each ink container is connected to the correspondent recording head as each ink container is mounted in the holder, so that installation mistakes are prevented.
According to the third of such methods, the external surface of each ink container is provided with a projection, the shape or structure of which is made different from those of the other ink containers different in ink color, and the ink container holder is provided with indentations or grooves in which the projections fit, and which are matched in shape or structure to the correspondent ink containers so that installation mistakes can be prevented.
In recent years, various advancements have been made in the field of an ink jet printer; it has become possible to print high quality images with the use of an ink jet printer, and also to use various types of ink. It has been known that the resistance of an image to water or friction can be improved by using two inks of different type so that the two inks solidify and fix to a sheet of recording medium by reacting to each other. Should an ink container be installed to a wrong position when this kind of method is employed, a recording head will be seriously damaged in function and the recorded images will be quite inferior. Thus, it is required that an ink container to be removably mounted in an ink container holder is provided with a highly precise and reliable identification structure, and also that the ink container is provided with a leak-proof ink outlet (with durability).
The above described conventional installation mistake prevention methods, however, had the possibility of suffering from problems. For example, in the case of the first example, an installation mistake was caught after the installation, and therefore, it was possible that inks were mixed and solidified, causing various problems: ink ejecting holes were plugged; ink failed to be ejected; a portion or portions of a printed image were missing; and a printer sustained various types of damage. In addition, it was possible that in the case of an apparatus which employs an exchangeable type ink container, ink containers were unnecessarily exchanged with fresh ones.
In the case of the second example, it did not occur that an ink container was installed all the way to a wrong position, but before an installation mistake was caught, the joint portions were placed in contact with each other. Therefore, it was also possible that the inks would mix and solidify, causing various problems, that is, ejection failure, printing of images with a missing portion or portions, and apparatus breakage. Also in this case, there was a possibility that in the case of an apparatus which employs an exchangeable type ink container, ink containers were unnecessarily exchanged with fresh ones.
In the case of the third example, an installation mistake was physically prevented, which reduced the possibility of ink mixture such as the one described above. However, the ink container shape was complicated, in particular, when an ink container provided with an identification structure was formed in a single piece. Therefore, there were problems that the ink container cost was high, and also that an ink container was limited in terms of material.
Various publications, in particular, EP0738605, disclose an ink container which is formed by blow molding. This ink container comprises a hard external shell in the form of an approximately polygonal prism, and a liquid holding portion (hereinafter, it may be referred to as xe2x80x9cinternal bladderxe2x80x9d) which holds liquid therein. When the liquid holding portion is full, it is virtually identical, or very similar, in shape to the internal space of the shell. It changes in shape as the liquid therein is drawn out. Hereinafter, this type of an ink container may be referred to as multilayer container. As described in the aforementioned publications, it is excellent in terms of ink storage ratio, and also the ink usage ratio. However, there is a possibility that various problems will occur as its shape becomes complicated.
To begin with, it is generally difficult to form a highly precise object with the use of blow molding; it is difficult to form a precise and reliable identification structure on an ink container.
Further, as the ink is drawn out of the ink holding portion of the aforementioned ink container, the ink holding portion must properly shrink so that the liquid is supplied out of the ink holding portion while generating negative pressure therein. The shape of the internal bladder corresponds to the shape of the ink container external shell, and therefore, if the shell shape is complicated because of the presence of the irregularities on the surface of the shell, it is difficult for the internal bladder to deform as the ink is drawn out, and if the internal bladder fails to properly deform, the ink fails to be reliably supplied. In other words, there is a possibility that the ink cannot be reliably supplied from an ink container such as the aforementioned one, and in the case that the shell shape is more complicated, there is a possibility that pin holes may develop in the wall of the internal bladder.
On the other hand, it is desired that in the case of an ink jet head cartridge structured so that ink containers can be removably connected to the recording head portion of the ink jet head cartridge as described above, the joint portion between the ink container and the recording head portion, to which the liquid in an ink container is supplied, simultaneously satisfies at least the following requirements.
One of the requirements is that when an ink storing (or accommodating) container or is connected to, or separated from, to a component to which ink is to be supplied, ink does not leak from the joint portion regardless of the attitude of the ink storing container. Another of the requirements is that the ink can be steadily supplied after the completion of the connection. An additional requirement, which is necessary in consideration of the possibility that some users may repeat the processes of connecting and separating, is that the preceding two requirements, which must be satisfied when the connection or separation occurs, must be satisfied in spite of the repetition of the connecting and separating processes.
Thus, the inventors of the present invention paid attention to a means for sealing the joint opening of an ink container, more specifically, a valve mechanism which opens or closes the joint opening, in particular, such a valve mechanism that keeps the joint opening sealed when the ink container is not in connection to the ink jet head cartridge, and opens the joint opening as the joint pipe of the liquid receiving party is pushed into the ink outlet of the ink container, and that returns to its original position, or sealing position, to seal the joint opening as the joint pipe is separated from the joint opening.
However, the assumption of the installation of a valve mechanism unit in the liquid outlet of a liquid container led to the discovery of a fresh technical problem that if the valve mechanism is exposed from the liquid container, the valve mechanism drops out of the liquid outlet or becomes dislocated in the liquid outlet due to external causes, for example, when the liquid container is dropped.
The primary object of the present invention is to provide an ink container, in the form of the aforementioned multilayer container which is superior in liquid storage ratio and usage ratio, and is provided with an inexpensive and reliable mechanism for preventing installation mistakes, without negatively affecting the advantage of the multilayer container, that is, the stability in the negative pressure when the ink container is in use.
The second object of the present invention is related to, solely or in addition to the above described first object, an ink container having an installation mistake prevention mechanism which comprises a valve placed in the ink delivery opening portion, and to provide an ink container which does not suffer from the aforementioned new technical problems regarding an ink container having a valve in the ink delivery opening portion.
The third object of the present invention is related to, solely or in addition to the above described first object, an ink container having a valve in the ink delivery opening portion, and is to provide an ink container which assures that liquid does not uselessly leak from the valve unit and opening portion.
The remaining object of the present invention is to provide various inventions related to the valve unit usable in the above described ink container, an ink container manufacturing method, an ink jet head cartridge in which the ink container is mounted, an ink jet recording apparatus, and the like.
The ink container in accordance with the present invention is characterized in that in order to accomplish the aforementioned first object, it is removably mountable into or onto a dedicated installation space, and that it comprises: an liquid storing member comprising an external shell, which has an opening and is in the form of an approximately polygonal prism, and an internal multilayer bladder, which is virtually identical, or very similar, in shape to the internal space of the shell, and is capable of deforming as the liquid stored therein is drawn out; and an identification member for identifying the type of liquid in the liquid storing member.
Since the aforementioned ink container comprises the liquid storing member for storing liquid, and the identification member for identifying the liquid in the liquid storing member, when manufacturing a plurality of ink containers for inks of different color, the liquid storing member may be manufactured as a common component. This reduces cost. Separating the ink container into two subsections, that is, the identification member and the liquid storing portion, makes it possible to form the liquid storing portion, namely, a container with a multilayer wall, with the use of multilayer blow molding, and the identification member, which requires a higher degree of dimensional accuracy, with the use of injection molding. Therefore, it is possible to realize an ink container which guarantees more stable ink delivery, and more accurate identification, compared to a container which is provided with the identification function, and is formed as a single piece component.
The ink container in accordance with the present invention is characterized in that in order to accomplish the aforementioned second object, it comprises a liquid storing member, which has an opening portion for drawing ink out as well as storing ink, and an identification member for identifying the liquid in the liquid storing member, and which is removably installable into or onto a dedicated installation space, and the valve unit, which allows the liquid in the liquid storing member to be drawn out, and is located in the opening portion of the liquid storing member; that the identification member is provided with an ink delivery opening, which covers the joint portion between the valve unit and liquid storing member, and is located adjacent to the periphery of the liquid path of the valve unit; and that the identification member is almost immovably but removably fixed to the liquid storing member with the use of a joining means which allows the former to be easily disjoined from the latter.
According to the above described ink container, the identification member can be used as the cover for protecting the valve unit and opening portion, and the identification member and liquid storing member are joined to each other with the use of a method which allows the former to be easily disjoined from the latter. Therefore, the valve unit and opening portion are not subjected to excessive force. Therefore, it is possible to provide an ink container which does not suffer from the new problems of the container equipped with a valve, that is, such a problem that the valve mechanism drops out or shifts due to falling or other external influences.
The ink container in accordance with the present invention is characterized in that in order to accomplish the above, it has a valve unit for supporting the valve mechanism which can be opened or closed, in the ink delivery opening portion, and the protective cover for protecting the joint portion between the valve unit and the main assembly of the ink container, is positioned adjacent to the periphery of the liquid path of the valve unit.
According to the above described ink container, the valve mechanism is effectively prevented from dropping out or shifting by the protective cover, and the occurrence of a fresh leak is prevented by the contact area between the valve mechanism and protective cover, which are unitized with each other as the protective cover is attached. As a result, it is possible to provide an ink container which assures that the useless liquid leakage from the valve unit and opening portion can be prevented.
The valve unit in accordance with the present invention is characterized in that it comprises: a cylindrical valve body (or frame); a valve plug (or member) in the form of a piston which freely slides in the valve body; a supporting member which is joined to the one end of the valve body, and supports a portion of the valve plug in a manner to allow the plug to freely slide; a resilient member for generating constant force in the direction to push the valve plug away from the supporting member; a contact portion which is located along the inwardly facing surface of the valve body, and makes contact with the end of the valve plug under the pressure from the resilient member; an elastomer layer, which is placed on the interior surface of the valve body, covering from the position of the aforementioned contact portion to the other end of the valve body, and the portion of which constitutes the aforementioned contact portion; an opening which becomes disconnected from the opening on another end of the valve body as the end of the valve plug comes into contact with the aforementioned contact portion; and a flange which radially extends from the periphery of the other end of the valve body, wherein the position of the plane of the front surface of the flange is different from the plane of the opening of the valve body, on the flange side.
According to the above described valve unit, the opening end of the valve body, on the liquid delivery opening side, is made to project from the surface of the flange, and therefore, when the peripheral portion of the opening of the protective cover of the ink container is joined to the flange, the open end of the valve body can be positioned in the aforementioned opening portion. As a result, the elastomer layer which was placed on the inward surface of the valve body is exposed at the inward side of the opening of the aforementioned external protective member; in other words, the area coated with the elastomer layer is expanded onto the periphery of the aforementioned liquid delivery pipe, turning the valve mechanism into a highly reliable one which does not allow liquid to leak when liquid is supplied through the aforementioned liquid delivery pipe.
The ink container manufacturing method in accordance with the present invention is characterized in that it is a method for manufacturing an ink container comprising: a liquid storing member which stores liquid and is provided with an opening for drawing out the liquid therein, a valve unit placed in the opening of the liquid storing member, and an identification member which is used for identifying the type of the liquid in the liquid storing member and is provided with an ink delivery portion which covers the opening of the ink storing member, and that it comprises: a fixing process for fixing the valve unit to the liquid storing member, and a joining process for joining the liquid storing member to the identification member with the use of a joining means which allows the former to be easily disjoined from the latter, after the valve unit is fixed to the liquid storing member.
According to the above described ink container manufacturing method, the ink container for accomplishing the second object of the present invention can be easily manufactured.
The present invention is also related to an ink jet head cartridge and an ink jet recording apparatus, in which the above described ink container is mounted.
The ink jet head cartridge in accordance with the present invention is characterized in that it comprises a space into which the above described ink container is removably installable, and a recording head portion for ejecting the liquid in the ink container installed in the above ink container space, and that it comprises an identifying portion for identifying the identification member with which the ink container is provided.
The ink jet recording apparatus in accordance with the present invention is characterized in that it comprises the above described ink jet head cartridge, and a moving means for moving the ink jet head cartridge and recording medium relative to each other, and that it can record on the recording medium by ejecting ink from the recording head in response to electrical signals for ejecting the liquid.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.